Safety control for auto engines



Oct. 19, 1937. c. M. TANNVR SAFETY CONTROL FOR AUTO ENGINES Filed Dec. 19, 1936 2 Sheets-Sheet l 1N VENTOR. 72H/VER.

C24/wwf /l ATTORNEY.

Oct. 19, 1937. c. M. TANNER SAFETY CONTROL FOR AUTO ENGINES Filed Dec. 19, 1956 2 Sheets-Sheet 2 l. l n l l n l l l v Y w i i i Sys fe #r1 I. mvENToR; C2 49E/v0.6 /v/vf/P.

ATTORNEY.

Patented Oct. 19, 1937 UNITED STATES PATENT OFFICEv Schin.

This invention relates to an automatic electric switch for automobiles and has forits principal object the provision otra m which will shut off the entire electrical Supply t the auto- .5 mobile and its engine in caseof motor failure or other accidental cause; which will automatically stop the motor whenthe latter rims out of oil and prevent operation of the motor without oil;

` which will act asa theft lock to prevent unauthorized starting of the motor; and which will prevent accidental draining of the battery by the lights, radio, heater, ignition, etc., when the car is notin use.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and emciency.

These will become more apparent from the following description.

In the following detailed description=of the invention reference is had to the accompanying drawings which form a part hereof. Like numeralsrefertolikepartsinallviewsofthe drawings and throughout the description.

In the drawings:

Fig. 1 illustratesa plan view of the important automatic switch with the cover plate removed to show the interior construction.

Fig. 2 is a longitudinal section, thereof, taken on the line 2v2, Fig. 1, illustrating the switch in the open position.

Fig.3isasimilarsectionillustratingtheswitch i-I Fig. 3. Pig. adetail viewcfthecontrol handle. lg.7isawirlngillustratingthecir cuit employed withtheinvmtion. Y Theinventionisencledinasuitable metal caseorhousingllwhichmaybeclosedbymeans of a suitable lid The is provided with attachment bolts I2, by means of which it maybesecured'toanymltablemelalpartofthe Prefsureissmliedtotbecylinderthmgh a-xn'essnrepipenawhichwhminweiscon- Wnectedmtheollpresurelinedtbeautcmobllc.

(cl. m2)

The extremity of the piston rod I3 terminates in a latch member 22,` which is hinged upon the piston extremity Vby means of, a suitable hinge pin 23. A moveable switch arm 2l is hinged to the bottom of the housing Il, upon a suitable hinge 25, immediately ahead of the cylinder I3. A spring 26 acts to constantly force the switch arm 2| toward a switch contact 21 secured upon the extremity of the case Il.

l The contact 21 terminates in an electrical contact lug 23, for receiving an electrical lead 39 from the battery to the ground. The moveable arm 2l is slotted for the passage of the latch 22 and carries a latch pin 23, over which the latch rldes.- A suitable leaf spring 3l presses the latch 22 downwardly against the pin 23.

The ground return lead 33 from the car battery, indicated at 3|, is connected to the contact lug 23 and the case or housing Il is grounded through the bolts I2 to the carframe.V Thus, all of the current returning from the car electrical system flows from the ground through the case I3, the moveable switch arm 2l, the contact 21, the lug 23, and the lead 33 to the battery 3|.

Let us assume that the engine is running. The oil pump of the engine is supplying pressure through the supply pipe 2| to the cylinder |3to force the piston |1 forward, and the latter is Y holding the switch arm 24 forwardly against the contact 21 to close the electrical circuit ot the engine. Let us assume that the oil supply of the engine fails, this causes a decreased preureV in the cylinder I3 andallows the spring I! to force the piston inwardly, this causes the latch 22 to pull the moveable contact 24 away from the contact 21, thus breakingthe circuit, shutting oi! the electrical supply, and stopping the engine. Letusnowassumethattheoilsupplyhasbeen restoredandisdesiredto againstarttheengine. thiscannotbedonewiththecontactsuandn separated, so some initial means must be provided for bringing these contacts together. This is aecomplishedby meansqt a latch lifting lever V32hinged within the'case Il upon a hinge bolt 33. A iiexible wire 3l, within a flexible tube 35 issecuredtothelever32. Thewire extendsto a control knob 36 which may be mounted upon -the instrument board of the automobile or in any other suitable position. When the knob 36 is drawn out, it lifts tbe extremity of the lever 32, cauaingthelattertoliftthelatch 22 fromthe pin 23. This allows the spring to snap the switcharm 2l against the contaet21 to allow themotortostart. Assoonasthemotorstarts mbacisreieaedtoasainmsasethelmn the battery were cut out this generator would supply sucient current' to operate the engine.

Therefore, some means must be provided to short circuit the generator `before the battery is cut out, this isaccomplished by means of a leaf spring contact 3l, extending from a generator screw 38 into the opening path of the switch arm always shorted before the nal contact is broken between the arm 2d and the springs so that the generator is out of circuit before the battery. A small drain hole l2 is drilled through the cylinder i3 aheadI of the piston to drain out any oil which may leak past the sealing washer I8.

It can be readily seenthat the device serves many useful functions. As above described, failure of oil will stop the engine. Another function -is that it prevents the driver from accidentally leaving his lights, radio, heater, or other electrical devices on, when he leaves the car, thereby draining the battery. As s'oon as he fstops the engine all of these devices will be automatically cut out of circuit. It also acts as theft lock, as an ordinary automobile thief is unaware that it is necessary to operate the knob 36 before the engine can be used.

While a specic form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, Within the scope of the appended claims, without departing from the spirit ofthe invention.

Having thus described the invention, what is claixined and desired secured by Letters Paten j pressure cylinder; a piston in said cylinder; a piston rod extending from said piston through one extremity of said cylinder;.a rst spring'- urging said piston into said cylinder;-a stationary electrical contact; a movable electrical contact; a

- second spring urging said movable contact toward said stationary contact; means on said pis' ton rod for engaging and pulling said movable contactv away from said stationary contact as said piston moves into said cylinder; and manually operated means for releasing said piston rod from said movable contact when desired 'to allow said second spring to close said contacts. A

2. A pressure operated sWitch'cOmprising: a pressure cylinder; a piston in said cylinder; a

piston rod extending from said piston through 0ne.extremity of' said cylinder; a first spring urging said piston intofsaid cylinder; a stationary electrical contact; a movable electrical con# tact; a, second spring urging'. said movable contact toward'said stationary contact; a latch member on the extremity of said piston rod; an engaging member on said movable contact to Abe engaged by said latch member so that said piston rod will act to separate said contacts as said piston mgps into said cylinder; and -means for releasing said ltch member from said movable contact when esired.v

1. A pressure operated switch comprising: a

aoeaaoi 3. A pressure operated switch comprising.' a pressure cylinder; a piston in said cylinder; a piston rod extending from said piston through one extremity of said cylinder; a first spring urging said piston into said cylinder; a stationary elec-` trical contact; a movable electrical contact; a second spring urging said movable contact toward said stationary contact; a latch member on the extremity of said piston rod; an engaging member on said movable contact to be engaged by said latch member so that said piston rod will act to separate said contacts as said piston moves into said cylinder; a lever extending beneath said latch member; and means for raising said leverto Cause v the latter to lift said latch member out of engagement with said engaging member. v

4. A pressure operated switch comprising: a pressure cylinder; a piston in said cylinder; a piston rod extending from said piston through one extremity of said cylinder; a rst spring urging said piston into said cylinder; 'a stationary electrical contact; amovableelectrical contact; a second spring urging said movable contact toward said stationary contact; alatch member on the extremity of said piston rod; an engaging member on said movable contact to be engaged by said latch member so that-said piston rod will act t0 separate said contacts as said piston moves into,

said cylinder; means for releasing said latch mem.-

ber from said movable contact when desired; and

means for preventing rotation of said piston rod in said cylinder so that said latch member will always be maintained in operative position.

5. A safety switch for cutting olf the battery of an automobile in consequence of a reduction in the oil supply pressure tothe engine thereof comprising: a pressure cylinder; means for connecting said cylinder to the oil supply of an engine; a piston in said cylinder to be moved outward by the pressure in said cylinder; a spring acting to force said piston against said pressure; a stationary contact; a hinged contact; a spring for urging said hinged contact against said movable contact;

-a piston rod extending from said cylinder; a

hooked latch member hinged to the extremity of .said rod so as to engage and-withdraw said n iovable contact from said stationary contact; means for releasing said latch member when desired; and means for placing said contacts in the battery circuit of an automobile.

^ 6. A safety switch for cutting oi the battery of an automobile in consequence of a reduction in the oil pressure to the engine thereof comprising: a pressure cylinder; means for connecting said cylinder to the oil supply of an engine; a piston in said cylinder toV be moved outwardv by the pressure in said cylinder; a spring acting to force said y piston against'said pressure; a stationary contact; a hinged contact; a spring for urging said hinged contact against said movable contact; a piston rod extending from said cylinder; a hooked latch `member hinged to the extremity of said rod so as to engage and withdraw said movable contact from said stationary contact; means for releasing said latch member when desired; means for placing 'said contacts in the battery circuit of an automobile;` auxiliary contacts in the path of said movable contact to close a. second circuit before the rst contacts open; and means for placing said auxiliary contacts in circuit with the generator circuit of an automobile.

CLARENCE M. TANNER. 

